Android入门之ActionBar兑现Tab导航

Android入门之ActionBar实现Tab导航

效果图：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="jk.actionbartab"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="11"
        android:targetSdkVersion="17" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="jk.actionbartab.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="action_settings">Settings</string>
    <string name="app_name">Tab导航</string>
    <string name="title_activity_main">ActionBar的Tab导航</string>
    <string name="personal_page">个人</string>
    <string name="query_page">查询</string>
    <string name="pay_page">支付</string>

</resources>

MainActivity.java

package jk.actionbartab;

import jk.actionbartab.R;
import android.app.ActionBar;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentTransaction;
import android.os.Bundle;

public class MainActivity extends Activity implements ActionBar.TabListener {
	private static final String SELECTED_ITEM = "selected_item";

	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		final ActionBar actionBar = getActionBar();
		// 设置ActionBar的导航方式：Tab导航
		actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
		// 依次添加3个Tab页，并为3个Tab标签添加事件监听器
		actionBar.addTab(actionBar.newTab().setText(R.string.personal_page)
				.setTabListener(this));
		actionBar.addTab(actionBar.newTab().setText(R.string.query_page)
				.setTabListener(this));
		actionBar.addTab(actionBar.newTab().setText(R.string.pay_page)
				.setTabListener(this));
	}

	public void onRestoreInstanceState(Bundle savedInstanceState) {
		if (savedInstanceState.containsKey(SELECTED_ITEM)) {
			// 选中前面保存的索引对应的Fragment页
			getActionBar().setSelectedNavigationItem(
					savedInstanceState.getInt(SELECTED_ITEM));
		}
	}

	public void onSaveInstanceState(Bundle outState) {
		// 将当前选中的Fragment页的索引保存到Bundle中
		outState.putInt(SELECTED_ITEM, getActionBar()
				.getSelectedNavigationIndex());
	}

	public void onTabUnselected(ActionBar.Tab tab,
			FragmentTransaction fragmentTransaction) {
	}

	// 当指定Tab被选中时激发该方法

	public void onTabSelected(ActionBar.Tab tab,FragmentTransaction fragmentTransaction) {
		// 创建一个新的Fragment对象
		Fragment fragment = new DummyFragment();
		// 创建一个Bundle对象，用于向Fragment传入参数
		Bundle args = new Bundle();
		args.putInt(DummyFragment.ARG_SECTION_NUMBER, tab.getPosition() + 1);
		// 向fragment传入参数
		fragment.setArguments(args);
		// 获取FragmentTransaction对象
		FragmentTransaction ft = getFragmentManager().beginTransaction();
		// 使用fragment代替该Activity中的container组件
		ft.replace(R.id.container, fragment);
		// 提交事务
		ft.commit();
	}

	public void onTabReselected(ActionBar.Tab tab,
			FragmentTransaction fragmentTransaction) {
	}
}

DummyFragment.java

package jk.actionbartab;

import android.app.Fragment;
import android.os.Bundle;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

public class DummyFragment extends Fragment {
	public static final String ARG_SECTION_NUMBER = "section_number";

	// 该方法的返回值就是该Fragment显示的View组件
	public View onCreateView(LayoutInflater inflater, ViewGroup container,
			Bundle savedInstanceState) {
		TextView textView = new TextView(getActivity());
		textView.setGravity(Gravity.CENTER_HORIZONTAL);
		// 获取创建该Fragment时传入的参数Bundle
		Bundle args = getArguments();
		// 设置TextView显示的文本
		textView.setText(args.getInt(ARG_SECTION_NUMBER) + "");
		textView.setTextSize(30);
		// 返回该TextView
		return textView;
	}
}